Silane or silanol priming solutions have been used for many years for priming and repair of dental materials such as porcelain, metals, alloys and dental composites. These primers typically are sold as two-part products which are mixed together prior to use, or as one-part products which are used as is.
Representative two-part products include "Fusion" liquid surface primer (George Taub Products and Fusion Co., Inc.) and "Silanit" porcelain repair material (Vivadent). The "A" portion of the Fusion product appears to be approximately an 85:15 weight percent water:isopropanol solution with a pH of 4.7, and the "B" portion appears to be approximately 12 to 15 weight percent gamma-methacryloxypropy/trimethoxysilane dissolved in isopropanol. Equal volumes of the A and B portions are mixed together and allowed to stand for 15 minutes prior to use, forming a clear silanol solution containing approximately 43:50-52:6-8 weight percent water:isopropanol:silanol. The mixture is said by the manufacturer to be stable for about three weeks after mixing if stored under refrigeration or in a cool dark area. After that time the mixture becomes cloudy (due to solution condensation of the hydrolyzed silanol to form insoluble dimer, oligomer, or polymer) and must be discarded.
The "A" portion of the Silanit product appears to be approximately a 56:44 weight percent water:isopropanol solution with a pH of 4.6, and the "B" portion appears to be substantially pure gamma-methacryloxypropyltrimethoxysilane. The A and B portions are mixed together in a 5:1 ratio and allowed to stand for 15 minutes prior to use, forming a clear silanol solution containing approximately 47:37:17 weight percent water:isopropanol:silanol. The mixture is said by the manufacturer to be usable for about 24 hours after mixing. After that time the mixture becomes cloudy and must be discarded.
Representative one-part products include "Kerr" porcelain repair primer (Sybron Corp.) and "Den-Mat" porcelain repair bonding agent (Den-Mat Corporation). The Kerr product appears to be approximately 5 weight percent gamma-methacryloxypropyltrimethoxysilane dissolved in ethanol. This product also appears to contain about 0.4 weight percent water (as measured by Karl Fischer analysis) and has a pH of about 6.8. The Den-Mat product is described in U.S. Pat. Nos. 4,117,595, 4,256,603 and 4,294,349, and appears to be a mixture of approximately 5 weight percent gamma-methacryloxypropyltrimethoxysilane and 2.5 weight percent gamma-glycidoxypropyltrimethoxysilane in n-butanol. Each of these one-part products contains essentially completely unhydrolyzed silane when in solution. Each is applied to an acid-treated substrate and allowed to stand while the silane hydrolyzes in situ due to the action of acid and adventitious moisture.
Other silane or silanol priming solutions for use in dentistry are described in U.S. Pat. Nos. 3,369,297, 3,423,828, 3,423,829, 3,423,830, 3,423,831, 4,200,980, and in Semmelman et al., "Silane bonding Porcelain Teeth to Acrylic", J.A.D.A., 76, 69-73 (1968). Properties of silane and silanol solutions in general are discussed in Lee, "Wettability and Conformation of Reactive Polysiloxanes", J. Colloid and Interface Science, 27(4), 751-760 (1968), Lee, "Wettability of Organosilanes. I. Wettability and Conformation of Reactive Polysiloxanes on Silicate Glass Surface", Soc. Plastic Ind., sec. 9D, pp. 1-14 (1968), Rosen, "From Treating Solution to Filler Surface and Beyond", J. Coating Technoloqy, 50, 70-82 (1978), and Pluddemann, "Silane Coupling Agents", Ch.3, 49-73 (New York, 1982). Other patents relating to silane or silanol solutions include U.S. Pat. Nos. 3,976,497, 3,986,997, 4,101,513, 4,113,665, 4,195,141, 4,247,436, 4,341,213, 4,352,894, 4,368,313, 4,370,439, 4,396,650, 4,435,219 and 4,439,239.